Tuesday, November 27, 2012

Specifically, he makes his way in the world using "a set of heuristic guesses made by a jumped-up monkey with a set of brain circuits designed to detect whether the fruit is ripe or it is safe to jump to the next branch".

And of course, that's true of all of us.

I do not know Nagel, so I will not jump into that particular fight with Gene Callahan. But speaking of monkey brains specifically, Gene trots out the tired old "if it's just a heuristic guess or convenient fiction then you can't prove the claim - you're just guessing about the fact that you're guessing!".

Right. That's the point.

And you're just guessing too. The thing is, Brad and I know we're guessing.

The metric is not whether we have plumbed the depths of objective reality. That sounds like a good metric on paper, but it's not a metric that we have access to. Instead of criticizing Brad on the basis of a metric that neither Gene nor Brad have available to them, perhaps we should come up with a different metric. Something like "does this heuristic seem to help me navigate the world".

That doesn't pose the same sort of problems as the metric of consistency with objective truth. We may argue about it, but I don't see what's wrong with that. Gene and I may never agree about the claims that best help us navigate the world, but I Gene and I can both have more confidence in the sentence "this claim helps me navigate the world" than the sentence "this claim is consistent with objective truth".

That seems pretty good to me.

And it turns out that even though we have to accept a degree of pluralism and disagreement when we abandon "objective truth", we still seem to generate a fair amount of agreement. It's not hopelessly disordered. There seems to be enough consistency in peoples' subjective experience that we can generate a set of claims that a lot of people agree with.

What more could you ask for? That's pretty good for a monkey, right?

UPDATE: Nagel's way of thinking, of course, is itself a heuristic that does a decent job helping people navigate their world. It staves off existential anxieties, explains the order we see, reinforces social institutions, along with all sorts of other benefits. That's why it endures. That's even why it's worth talking that way sometimes. But that doesn't mean it is "true" in the "objective truth" sense of the word "true".

37 comments:

But you also claim to know that everyone else is just guessing. And that you appear to be certain about. Which undermines your whole claim to epistemic modesty. Which is why we advocates of reason have to keep making our "tired old claim," because you relativists keep entirely missing its point.

I can be immodest in some pursuits, but I don't think that's the case here. Obviously I could be wrong. That's implicit in calling it a guess. I don't think on questions about "objective truth" I'd even know if I were wrong - and that's not even implicit: that's the whole claim!

So what can I do? Well I could still assert it. It's not immodest because I have grounds to assert it - I assert it because nobody's demonstrated how we evaluate a sentence against an objective truth. So I feel in pretty good shape asserting we can't do that (if someone could I'm sure they'd have shown everyone else, right?). And I may be wrong, but it's an approach that seems to work well so far.

What's so immodest about that? In the very worst case I've goofed up and there is a way to evaluate our claims by comparing them to an "objective truth". But my whole perspective here is grounded on the point that we could very well be wrong so we should focus on usefulness of claims - so I'm not sure how actually being wrong would really upset that.

Granted - if I were wrong on objective truth I would have to abandon my usefulness method for evaluating claims. But that's OK. It wouldn't be useful anymore, after all.

This: "Granted - if I were wrong on objective truth I would have to abandon my usefulness method for evaluating claims. But that's OK. It wouldn't be useful anymore, after all."

Is just to say that pragmatism to a certain extent is just a more general methodology than rationalism (see my update above for a somewhat related point). I don't feel comfortable saying anything about objective truth. I do feel comfortable saying something about usefulness. If I ever became comfortable saying something about objective truth then of course I would, but I would because (1.) consistency with objective truth is a great measure of a claim, and (2.) it's the most useful method for evaluating claims.

I don't think that we know that Gene Callahan is just guessing. Perhaps his reason does have transcendent access to objective reality. Perhaps Thomas Nagel's does. The fact that when Nagel tries to give an example of such transcendent access he makes a complete fool of himself militates against it, and I would be surprised and astonished were it to be true, but it is not inconceivable. Perhaps, after all, Thomas Nagel is the alpha and the omega, temporarily hidden from us for inscrutable purposes, and he will reveal his true identity to us all at noon on Tuesday in Ward Circle, with Signs and Wonders. Could be. We could all be parts of some third-grader's history project in 2000000 AD, after all.

Before my night flight from London to San Francisco I would have given the odds that Thomas Nagel was the alpha and the omega as not too different from the odds that I would ever see the sun rise due south. I have seen the second. Perhaps I will see the first--or perhaps Thomas Nagel does have a reason with transcendent access to objective reality.

Nevertheless, the fact that Nagel can--after quantum mechanics!--claim that "everything we believe... has to be based ultimately on common sense, and what is plainly undeniable.... [W]e find it undeniable... that our clearest moral and logical reasonings are objectively valid" increases my confidence that it is highly, highly, highly likely that Nagel is simply confused, and it is highly, highly, highly, highly likely that he simply does not have the chops to play in this league.

Nagel's awe at the wonder of conscious reasoning is certainly his prerogative, but; his awe no more deserves attention than the awe of a baby-just-turned-toddler cupping his freshly minted faeces.

The toddler may think his faeces are the pure gestalt of a sacred covenant with the universe, and that their texture and his experience of it are an incontestable ode to his sublimation of the cosmos' truths.

Or, he could a juvenile man-monkey with a handful of faeces, and any neuron-fired thoughts he does or does not have before he puts his hand in his mouth are as meaningless as any other complex physical process both he and his faeces are a product of.

One last note. Does Gene Callahan have any idea what he is committing himself to in endorsing Thomas Nagel's claim to have transcendent access to objective reality? I think not:

>I decide, when the sun rises on my right, that I must be driving north instead of south, it is because I recognize that my belief that I am driving south is inconsistent with that observation, together with what I know about the direction of rotation of the earth. I abandon the belief because I recognize that it could not be true.... I oppose the abolition of the inheritance tax, it is because I recognize that the design of property rights should be sensitive not only to autonomy but also to fairness...

Why do you persist in bringing up this straw-man? TATOR does not mean that Thomas Nagel is always right. Only that there is an objective reality that we have the potential to access. Just because I sometimes make logic errors does not mean there is no such thing as logic or that nobody can do logic.

Maybe I'm wrong here, but I don't think that Nagel's objective truth argument is really about platonic forms like logic. It is more a response to Hume's questions, how do I know the color of the 101st goose? or how do I know that you see color the same way that I do? Questions about how sensory perceptions enter human consciousness and how we know them.

When it comes to logic and geometry there are theoretical problems that were known long before Nagel. Problems that make it quite problematic to assert them as objective. With logic we have Godel's theorem.(Some valid logical statements can be neither true or false, undermining the basic assumptions of logic) We have alternative axioms. (How do we know that our intuitive logic is the objectively true logic?) For geometry we have non-euclidean metrics. (How do we know that our intuitive grasp of geometry is correct? Answer: It isn't. It is an approximation that works well over short(ie human scale) distances. We're pretty sure that the geometry of reality is decidedly non-euclidean.)

TATOR would mean that the conscious impressions/representations of objects in the world are correct. But reasoning from reality, I can conclude(with probability, not certainty) that impressions formed by objects on my senses are often wrong, because evidence from my senses is often contradictory. (See optical illusions, color blindness, 4-color vision, non-pathological cognitive failures, pathological cognitive failures, and the day to day variance in cognitive function that humans experience due to periodic tiredness or sickness.) If I was getting objective reality, unmediated through some very fallible meat, I wouldn't get so much variance in my perceptions of what are (probably) the same objects in physical world.

Or taking another tack. So maybe Thomas Nagel isn't always right, but how does he *ever* know if he is accessing TATOR? or if he is making a logic error? To assert that TATOR is necessarily correct, you would have to have access to TATOR at the time that the time that you inferred that you have access to TATOR and know that you have access to TATOR at that time. It leads to some hucksterish silliness where every time there is a mistake or revision you need to say "Well it turns out that I didn't have access to TATOR last time that I said I did, I was just making a mistake, but this time I do, and this time, I really, really mean it." Really Nagel? Really?

I don't think Thomas Nagel can ever know for sure that he is correctly using his TATOR. But that is not to say he does not have TATOR. It just means that he needs to talk to other people who also have TATOR. The more other such people he talks to and the more of them check his work, the greater the confidence he can have that he successfully used his TATOR.

This is as far as I am taking the comparison to logic or arithmetic. I don't know per say that 2x=4 => x=2. I merely have a strong believe that when solving that equation I did the math correctly. However, it is possible that I made a mistake and so the more math-capable people check my work, the more I become confident that I solved the equation correctly.

This doesn't prove that the TATOR hypothesis is correct. But I think it does effectively refute Brad De Long's argument. Just because Brad De Long sometimes makes arithmetic errors does not mean he cannot do math. (much less that nobody can do math) It just means he is falliable. Similarly, just because Brad De Long does not always use his TATOR correctly does not mean that he does not have TATOR. Just that he is fallible.

Mind you, I'm agnostic on whether there is such a thing as objective reality and skeptical that we have transcendent access to it. I just have a compulsive need to jump on arguments which I think are bad. I'm seeing a therapist. ;-)

As far as mathematics and logic, I don't see those problems as problems. Sure, if you think math describes the world, those can be problems, but that's really an empirical question. If you see logic and mathematics as sets of rules, non-Euclidian geometry is just another set of rules. Godel's incompleteness theorem is just a cool way that the rules interact in unexpected ways. Just because a set of axioms doesn't describe the world or match intuitive logic or whatever doesn't mean that that set of axioms isn't real.

I'm a little unclear on what you're saying. If Nagel develops certainty that he is correctly seeing TATOR by talking to other people, people that look like just like him to his perceptions, how can that make him sure that they're both accessing TATOR, rather than expressing views which cohere to the same Darwinian heuristic?

I bring up the issues with logic/math not to imply that I think that they're bothersome for logicians or mathematicians, but only to point out that there are other equally(or more) accurate and consistent alternatives to the interpretations of math, geometry, and logic. As an example, let's take the case of general relativity. Our intuition suggests a euclidean metric for space, but general relativity suggests that this is not an accurate metric.

For someone, like Nagel, who thinks that thought and perception are somehow intrinsic to reality and extrinsic to brains, I would think this would be deeply troubling. If we perceive objective reality and are even necessary to it, why do we see it in the "wrong" way?

But for a neo-darwinist, it is simple. The reason we use a euclidean approximation is because our mental capabilities are constrained by the computational power of brains. If we had to solve the nigh intractable GR equations every time we had to determine whether to dodge left or right, we would be tiger food long before we get an answer. It seems that evolution explicitly favored practicality AND inaccuracy over the objective nature of reality.

The really worrisome problem for people like Nagel comes with the follow up question. If something as simple as how we perceive the distance between objects is less accurate than practical, what other aspects of our reason have been shaped in favor of inaccuracy?

p.s. I would argue that Godel is genuinely problematic, but the argument is not germane to the topic.

"Unknown" writes: "For someone, like Nagel, who thinks that thought and perception are somehow intrinsic to reality and extrinsic to brains"

I'm not sure Nagel really thinks they are "extrinsic to brains". His views on the relationship between minds and brains are pretty subtle. Some of his papers on the subject can be downloaded at his website:

http://philosophy.fas.nyu.edu/object/thomasnagel

I'm not quite sure what you mean by "extrinsic" so I don't want to claim for sure that Nagel would disagree with it.

Also, I don't think that Nagel claims that reason or intuition is infallible. I disagree with his pessimism about an evolutionary explanation the historical origin of our power to reason, even while agreeing with him that this power is part of an ability to (fallibly and partially, to be sure---and note that Nagel himself explicitly uses the qualifier "fallibly" in places) get in touch with objective reality. (It's a darned useful power, even though Nagel is not as impressed with its usefulness, in an evolutionary context, as I think he should be.)

Says Me: But ... doesn't the evidence suggest that human beings have been at least gloriously inconsistent with respect to their beliefs about objective reality? On both an individual and collective level? Assuming what we're now labelling "reason" is no different in its character to what we've always thought of as "reason", what makes you conclude that the most recent of these belief systems reflect "objective reality"?

Philosophy grad student here: I often don't know what people mean when they talk about "objective truths," but we can say that something is useful to believe, but not true, and conversely that there are "inconvenient truths." Also, it seems to me that whether something is really useful or not seems to qualify as an objective truth, at least on some accounts.

Nagel's problem, what I can make of it anyway, is that he thinks "pure reason" is a substantive thing with various powers to shape the world, at least via its possessors. I don't think worrying about "objective truth" is the way to go.

On the question of what we are justified in believing, we should just be sure to allow for degrees of justification - it's not a dichotomy between mere guessing on the one hand and complete certainty on the other. My belief that I have two hands is a hell of a lot more justified than any belief I might have about how many stars there are in the universe. One might reasonably think neither is completely certain, but neither are they equally "just guesses." Nagel claims we can have complete certainty about some special things, other people don't. Meh. I side with the latter, as well, but we don't have to throw the baby out with the bathwater and become complete pragmatists.

"Reason," "reality," and "access" are words that have a use in our lives. We learn the difference between true and false beliefs before we've had our first science class. And although science is essential in determining whether certain kinds of propositions are true or false, the meaning of “true” and “false” aren’t given by science; they are interwoven with the concept of a proposition among others.

Calling us “angelic reasoners” or “jumped up monkeys” conveys the image of a mind or a brain (plus senses) having some kind of contract with reality. This imagery misses all the concepts, language games, social practices, and forms of life through which we comprehend the things we do. It is human beings, not their minds or brains, that make estimates, arrive at judgments, and draw conclusions.

A bit more can be found here: http://www.the-human-predicament.com/2012/11/brad-delong-thomas-nagel-and.html

I haven't read the current Nagel book, but I've read a number of them. "The View From Nowhere" is astonishingly good, and it turns on the issue of metaphysical realism that seems to have everyone going right now. Metaphysical realism, as I understand it, is the view that objective reality may or may not be graspable by our conceptual schemes. Thus, quantum mechanics may (or may not) be the final word for us, and - even if it is - our inability to make it make sense (Einstein comes immediately to mind) may reflect the limitations of the human cognition apparatus.

I think Nagel's later work can be seen as attempting to draw out the implications of this view.

Re: "just because Brad De Long does not always use his TATOR correctly does not mean that he does not have TATOR. Just that he is fallible" Alas! If you have access to TATOR but because of your fallibility never know whether you are using your TATOR or your error rate and me and jumped up monkey logic, that is observationally indistinguishable from not having any TATOR at all. Thus I fail to see what your point might be--due to my jumped up monkey nature, of course

Re: "Does Gene Callahan have any idea what he is committing himself to in endorsing Thomas Nagel's claim to have transcendent access to objective reality?" Rather than defending Mr. Callahan, I ask you, Brad (whose blog is my first destination each morning), whether you arrive at your conclusions by a process of reasoning or are driven to them by the impact of various stimuli (inputs) upon your jumped up monkey brain (because I think your acceptance of the Science cum Hume cum Darwin view ultimately commits you to the latter view.

I for one remain unpersuaded either way of TATOR or JUML (jumped up monkey logic). In other words, I have yet to see an observable difference between the two hypothesis. Really Brad, I was just saying that your argument doesn't refute TATOR. Not that TATOR is true.

I think Brad means that the process of reasoning is just another name for various stimuli being applied to his jumped up monkey brain. On the other hand, being poked in the ribs and wanting to ask a question are two completely different things.

I agree that Brad seems to be claiming that "the process of reasoning is just another name for various stimuli being applied to his jumped up monkey brain." But those who hold this view also seem to be committed to the proposition that a person reasoning his way to a conclusion is just another name for the person being caused to reach this conclusion by the impingement of various inputs on his jumped up monkey brain.

@PrometheeFeu: I should've been clearer, but the point I wanted to make is that explaining why someone did something in terms of his reasons is different than explaining some piece of behavior as the outcome of a chain of causes. And to say that "the process of reasoning is just another name for various stimuli being applied to his jumped up monkey brain" seems to obliterate this distinction.

I don't deny that there are many scientists, many neuroscientists in particular, who would like to abolish this distinction along with the rest of folk psychology, but these arguments are open to strong objections. See, e.g., M.R. Bennett and P.M.S. Hacker, Philosophical Foundations of Neuroscience (Blackwell, 2003), and if you can find it, an audio recording of Bennett and Hacker debating Daniel Dennett and John Searle about these issues.

Yes. I think Brad does not find that to be a compelling distinction. And I am inclined to agree with him.

If you do have a link to such an audio recording, I would love to hear it. I have a full-time job so unfortunately, I can't spend as much time reading articles as I wish I could. Alternatively, if you want to present some of the more persuasive arguments, shoot. I'm sure we'll all be happy to read.

Humans can understand some elements of their weaknesses. For that reason they can conceive of stronger intellects than themselves, even if they don't embody them or they don't exist. So, they can conceive of a difference between a closer picture of reality and the one they see. That's all that's needed here.

It may be true that a human and some other creature both respond in fundamentally mechanical ways to inputs, but come to different conclusions. That doesn't affect types of reason or logic that apply to a problem regardless of the actor. "Logic" (or "Reason" or whatever) is an aspect of a proposed solution to a carefully formed problem, it's nothing to do with that solver. It doesn't require believing anything incredible about existing lifeforms.

I hate it when you lot talk about philosophy. I now agree with Greg Hill about something! I'm going to sleep and I'm going to spend tomorrow persuading myself that I'm wrong.

Consider Timothy Williamson's claim and how one's position would be effected by a stance (for or against) on this issue: "One can know something without being in a position to know that one knows it." Williamson, Knowledge and Its Limits at 114.